The subject of the invention is a device for marking a detachable tube-joint, for example, for supporting structures, gas and liquid transportation pipes; the said device comprising an at least partly threaded shank with a ring at both ends and an appliance for moving the shank, located at the central part of the shank, one of the rings being threaded and connected to the shank by the thread, and both rings pressing a springing retainer to the internal wall of the tube, the end surface of the retainer resting on a supporting surface perpendicular to the axis. The device according to the invention is suitable for enabling the quick assembly of the tubes of supporting structures, e.g. of tubular furniture; it may be used, however, for any application requiring the accurate, stable securing in a specific position, of tubes or various appliances placed on tubes, so that the tube-joint is aesthetic and easily and quickly fitted together. Tubular systems assembled with the device according to the invention have a high load-bearing capacity and are easily made suitable for the transportation of gases or liquids, also.
Various solutions are known for the assembly of tubes. Such solutions are presented, for example, in patent descriptions DE-A-2 326 640, U.S. Pat. No. 4,903,924, EP 477 707 and HU 213285. For this latter example, the joining of the tubes is made possible by a device comprising rings, coned on the outside, and retainers, coned on the inside and slit along a generating line that can be pushed apart by the rings, both being located on a threaded shank, as well as a propelling appliance located at the middle of the shank, one of the rings connected to the shank by a thread. Although this solution creates stable and aesthetic fastening, it has the disadvantage that, if the propelling appliance is tightened too hard, the coned rings may get stuck inside the coned retainers, which makes detachment troublesome.
The object of the invention is the creation of a device, by eliminating the said disadvantage, which enables the making of a stable and aesthetic joint between tubes, easy to join and to detach. A further object of the invention is ensuring that it can be applied for joining pipes used for the transportation of liquids and gases.
The invention is based on the recognition that the desired goal may be achieved if, in the solution according to the above-mentioned patent description HU 213285, the ring is not coned and the stressing force is not generated between the touching cones; instead, the rolling points of the balls convey the stressing force from the ring to the retainer, slit along its generating line or, if the ring is not coned, and the stressing force is not generated between the touching cones; instead, the retainer itself is made of an elastic material, pressing against the tubes to be connected when pressed together. In the case of pipes used for the transportation of liquid or gas, a solution to ensure free flow inside the shank of the connection device as well as appropriate sealing at the joints is established.
The invention is, therefore, a device for making a detachable tube-joint, for example, for supporting structures, gas and liquid transportation pipes; the said device comprising an at least partly threaded shank with a ring at both ends and an appliance for moving the shank, located at the central part of the shank, one of the rings being threaded and connected to the shank by the thread, and both rings pressing a springing retainer to the internal wall of the tube, the end surface of the retainer resting on a supporting surface perpendicular to the axis, the springing retainer being of a tubular shape on the outside, i.e. of a shape fitting that of the tube, whereas inside it is hollow and
the springing retainer has a coned surface inside as well as a slit along at least one of its generating lines, the ring being placed inside the retainer and are equipped with balls on their outside, resting on the coned internal surface of the retainers and the device has a construction preventing the turning away of the threaded ring and the respective retainer belonging to this threaded ring with respect to each other, or
the springing retainer is made of an elastic material and is placed around the ring, both rings being constructed in a way suitable for gripping the respective elastic retainers and suitable for the axial compression of the retainer while the shank is moving, and
in case of necessity, there is an axial bore-hole inside the shank.
It should be noted that, for the purpose of the interpretation of the invention, the threaded joint of the threaded ring to the shank is to be deemed equivalent to any other joint resulting in the longitudinal movement of the ring from the rotating movement of the shank.
If, in the solution according to the invention, the rings are equipped with balls on their outside, resting on the internal coned surface of the retainers, and the device has a construction preventing the turning away of the threaded ring and the respective retainer belonging to this threaded ring with respect to each other, it is practical if the appliance for the movement of the shank is constituted by a carrier device and a propelling unit for the movement of the carrier device, the carrier device is located on the shank and designed in a shape-locking way, preferably bordered by planes, and the diameter of the propelling unit preferably is equal with the external diameter of the tubes to be fitted together, and it is also practical if supporting surfaces for supporting end surfaces of the retainers, perpendicular to the axis, are located on the appliance used for the movement of the, shank, e.g. on its propelling unit.
In a preferred embodiment of the invention, a pivot is used for the prevention of the turning away of the threaded ring and the respective retainer with respect to each other, with one end secured inside the threaded ring and the other fitted into the slit along the retainer.
It may happen that a supporting appliance or a fitting is to be positioned at the tube-joint, possibly so it may be revolved. This is facilitated by the use of a spacer between the propelling unit and one of the retainers, for the positioning of fittings. Using a spacer, it is possible to connect tubes placed further away from each other.
In the case of pipes for gas or liquid transportation, a bore-hole is constructed in the shank in order to ensure free flow and the propelling unit is connected to the ends of the pipes, that means tubes, preferably through sealing rings in order to achieve the appropriate seal.
The device according to the invention is easily detachable from the tube ends. In the case of the irregularities of the figured surfaces, other methods may have to be used to facilitate detachability. This purpose could be served, for example, by the construction of an indent on the coned surface of the retainers as well as of raised collars on the propelling unit, the collars being clicked into the said indents.
If the springing retainer is made of an elastic material and is placed around the ring both rings being constructed in a manner suitable for gripping the respective elastic retainers as well as for the axial compression of the retainer while the shank is moving, it is practical if the ring is constituted by two opposing pieces sliding inside one another, equipped with a flange and a sheath, where the sheath of the first piece is threaded on the shank, whereas the sheath of the second piece is threaded on the first piece, and the thread is constructed inside the sheath of the first piece of the threaded ring connected to the shank.
Further, it is practical if the appliance for the movement of the shank is constituted by a carrier device, constructed in a shapelocking way, favourably bordered by planes, and a propelling unit for the movement thereof, the diameter of the propelling unit favourably being equal with the external diameter of the tubes to be fitted together; further, if, at the same time, there is on the appliance used for the movement of the shank, e.g. on its propelling unit, a supporting surface supporting, perpendicular to the axis, the flanges of the second pieces of the rings, and the flanges support the end surfaces of the elastic retainers perpendicular to the axis.
Using the device according to the invention, a safe and aesthetic tube-joint can very easily and quickly established, the detaching also being quick and easy as the device does not seize. The connection requires no treatment on the tubes, which can be secured in any position rotated around their axis. Further, the device may be applied to the connection of liquid and gas transportation pipes. The device can further be applied to the connection of other than cylindrical tubes, e.g. for quadrangle-section tubes as well.